#include <u.h>#define NOPLAN9DEFINES#include <libc.h> extern int _p9netfd(char*); static char *unknown = "unknown"; static intconvert(int s, struct sockaddr *sa, char **lsys, char **lserv, char **laddr){	struct sockaddr_un *sun;	struct sockaddr_in *sin;	uchar *ip;	u32int ipl;	socklen_t sn;	int n;	char *net;		switch(sa->sa_family){	case AF_INET:		sin = (void*)sa;		ip = (uchar*)&sin->sin_addr;		ipl = *(u32int*)ip;		if(ipl == 0)			*lsys = strdup("*");		else			*lsys = smprint("%d.%d.%d.%d", ip[0], ip[1], ip[2], ip[3]);		*lserv = smprint("%d", ntohs(sin->sin_port));		sn = sizeof n;		if(getsockopt(s, SOL_SOCKET, SO_TYPE, (void*)&n, &sn) < 0)			return -1;		if(n == SOCK_STREAM)			net = "tcp";		else if(n == SOCK_DGRAM)			net = "udp";		else{			werrstr("unknown network type");			return -1;		}		*laddr = smprint("%s!%s!%s", net, *lsys, *lserv);		if(*lsys == nil || *lserv == nil || *laddr == nil)			return -1;		return 0;	case AF_UNIX:		sun = (void*)sa;		*lsys = unknown;		*lserv = unknown;		*laddr = smprint("unix!%s", sun->sun_path);		if(*laddr == nil)			return -1;		return 0;	default:		werrstr("unknown socket family");		return -1;	}} NetConnInfo*getnetconninfo(char *dir, int fd){	socklen_t sn;	union {		struct sockaddr sa;		struct sockaddr_in sin;		struct sockaddr_un sun;	} u;	NetConnInfo *nci; 	if(dir){		if((fd = _p9netfd(dir)) < 0){			werrstr("no such network connection %s", dir);			return nil;		}	} 	nci = mallocz(sizeof *nci, 1);	if(nci == nil)		goto err;	nci->dir = smprint("/dev/fd/%d", fd);	nci->root = strdup("/net");	nci->spec = unknown;	if(nci->dir == nil || nci->root == nil)		goto err;	sn = sizeof u;	if(getsockname(fd, &u.sa, &sn) < 0)		goto err;	if(convert(fd, &u.sa, &nci->lsys, &nci->lserv, &nci->laddr) < 0)		goto err;	sn = sizeof u;	if(getpeername(fd, &u.sa, &sn) < 0)		goto err;	if(convert(fd, &u.sa, &nci->rsys, &nci->rserv, &nci->raddr) < 0)		goto err;	return nci; err:	freenetconninfo(nci);	return nil;} static voidxfree(void *v){	if(v != nil && v != unknown)		free(v);} voidfreenetconninfo(NetConnInfo *nci){	if(nci == nil)		return;	xfree(nci->dir);	xfree(nci->root);	xfree(nci->spec);	xfree(nci->lsys);	xfree(nci->lserv);	xfree(nci->rsys);	xfree(nci->rserv);	xfree(nci->laddr);	xfree(nci->raddr);	free(nci);}